atkinson



(No Model.)

. J, ATKINSON.

GAS ENGINE.

No. 306,712. A Patented Oct. 21, 1884.

2 Sheets-Sheet 1.

(IIIO Model.) 2 SheetSg-Sh'et 2. J. ATKINSON.

GAS ENGINE.

10.306,712. Patented 0201.11.1384. Y

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JAMES ATKINSON, LONDON, COUNTY OF MIDDLESEX, ENGLAND.

GAS-ENGINE.

,SPECIFICATION forming part of Letters Patent No. 306,712,` datedOctober 21, 1884.

Application filed- November i12, 1883. (No ntodcl.) Patented in England`September 2B, 188l,No. 4,086, and September 14,1582,

To @ZZ whom t may concern.-

Be it known that I, J Aims ATKINSON, a subject of the Queen of GreatBritain, residing at London, in the county of Middlesexl and Kingdom ofEngland, have invented certain new and useful Improvements in Gas-Engines, (for which I have obtained Letters Patent in Great Britain No.4,086, bearing date September 22, 1881, and No. 4,378, bearing dateSeptember 14, 1882,) of which the following is a specification.

My invention relates to improvements in gas-engines in which the poweris obtained by the ignition and subsequent expansion of a combustivemixture of gas and air, such gas and air` being exploded or ignited atatmospheric pressure, and the objects of my improvements are, rst, toprovide a main slide admitting gas and air and igniting the same,combined with a supplementary slide to regulate the exhaust, second, toprovide aseparate self -act` ing air-inlet, in combination with aslidevalve or valves for admitting gas and air, for the purpose of obtainingfull atmospheric pressure in the cylinder at the time of ignition,third, to cover the ignitionport excepting at the right time forignition. I attain these objects by the mechanism illustrated on theaccompanying sheets of drawings, in which- Figure 1 is a verticalsection through a gasengine embodying my improvements, and Fig. 2 is avertical elevation, partly in section, of the same engine.

Similar letters of reference indicate similar parts in each of thefigures, respectively.

I employ a vertical singleaeting open-top cylinder having a piston orplunger working in it, and by means of a connecting-rod driving anoverhead-crank in an ordinary manner. A small passage, A, from the underside, of the plunger communicates with the various ports in the insidecover,B. Betweenthis inside cover, B, and the outside cover, C,the mainslide D and the separate exhaust-slide E work almost without friction.The covers B and C are fixed denitely a certain distance apart, andthere are no springs on the outside cover, C. In these engines theslides are made very thin, being from one-fourth to one-half an inch inthickness in the various sizes, conseextent with the heat.

quently they do not expand to any material Though made to move perfectlyeasy between the two covers B and C, they are practically kept tight bymeans of a film of oil, thus working satisfactorily without any materialwear or friction, and as the Voutside cover,O,is screwed dead againststrips on the inside cover, B, an unmechanical atv` tendant cannot gripthe slides D and E so as tocause them to cut. The main slide D is driventhrough a connecting-rod by a small crank-pin, F, fixed in a disk, G,attached to one end of the crank-shaft. The engines are reversible byshifting this disk G round in relation to the main crank, the slidecrank-pin E being adjusted so as to be alittle behind the main crank inwhichever direction it is going.

The working ofthe engine is as follows: When the piston is at the bottomof its stroke, as shown in Fig. 1, Sheet 1, two ports, I-I and I, in theouter face of the main slide D are just commencing to open into twocorresponding ports, J and K, in the face of the outer cover, C. Therising plunger draws in air through these higher ports, H and J, and gasthrough these lower ones, Iand K. These two ports H and Iin the outerface of slide D run into one port, L, on the inner face of the slide D,thus thoroughly intermingling the entering gas and air which form anexplosive mixture, which passes through the highest port, M, in theinside cover,B, filling the passage A to the under side of the pistonand the cylinder itself, until the piston has made from i aboutone-third to about one-half of its stroke,

(the smaller proportion for larger engines and the larger proportion forsmaller engines,) during which time the admission-ports H, I, J, andKhave opened and closed again.

As soon as the admission-ports II I J K are cutoff a small ignition portor passage, N, in the slide D is opened to a similar port or passage, O,in the inside cover,B, the slight amount IOO of the cylinder areignited. Vhen the piston arrives at about the top of its stroke, themain slide D is approaching the top of its stroke. At the lower end ofthe main slide D there are projections Q, which engage similar projections, It, on the exhaust-slide E, which draws up this exhaust-slideE, and a passage, S, in the exhaust-slide E opens correspondingpassages,T and V,in the inside and outside covers, B and C, allowing theexhaust to pass from the cylinder into the exhaust-pipe V during thewhole descent of the piston. Vhen the piston arrives at the bottom, theslide D also is approaching the bottom end of its travel, and pushesdown the exhaust-slide E, thus closing the eXhaust-ports'I and U.Fingers WV on the sides of the exhaust-slides E extend below it.

main slide D is descending at the time the ignition-ports N and O passeach other; but, being left behind with the exhaust-slide E when themain slide D is rising, it leaves the ignition-port N uncovered at theproper time for igniting, thus effectually preventing ignition exceptingat the proper time. As there is a slight interval between the time theadmissionports H, I, J, and K are cutting off and theignition actuallytaking place, and also as the area through these ports H, I, J, an-d Kis being contracted during the time they are cutting off, there would bea considerable decrease of pressure in the cylinder before ignition,which would act very prej udicially as regards the cconomical andsatisfactory working ofthe engine. I therefore provide a separateselfactin g valve, a, (see Fig. 2, Sheet 2,) opening inward. 'Ihis valvea may be of thi-n sheet india-rubber, copper, or similar material,opening and closing small holes b or grooves in the cover c. The passaged from this valve a, is covered by the plunger until the time when theadmissionports H and I in the slide D are closing, and is fully openwhen the ignition takes place. As the passages b through the cover c aremade of ample area, and the valve a is very tight, the pressure insidethe cylinder before ignition is practically atmospheric pressure. Theignition itself closes the valve c. To modify and reduce the concussionof air due to this valve a closing, I inclose it by means of a dome- Theair-passage 7L in vthe outer cover, C, terminates in a self-actingvalve, i, which prevents gas escaping if the engine should be leftstanding with the gas on in such a position that the ports I and K areopen.

Having fully described myinvention, what I claim,and desire to secure byLetters Patent of the United States, is-

l. A main slide-valve working between two surfaces and controlling theadmission of gas and air and flame for ignition, in combination withanexhaust-valve driven by the slide; valve by tapping it backward andforward between the same faces or surfaces, substantially as and for thepurpose set forth.

2. The combinat-ion, in a gas-engine, of the main slideD andsupplementary slide E with the air-valve a, substantially as described.

3. In a gas-engine, the combination of a slide-valve admitting gas andair, with a self'- acting valve admitting air during the Same stroke7 asset forth.

4. The finger Y, attached to the exhaustslide E, and operating theopening and closing of the ignition-port by the movements of the mainslide D, substantially as described.

JAMES ATKINSON.

lvitnesses:

JOSEPH GoRNELrUs IfIoLMns, GEORGE EDWARD PRIDDLE.

